Coarse wavelength division multiplexing (CWDM) applications were expanded to include use in which band?

Coarse Wavelength Division Multiplexing (CWDM) primarily utilizes the C-band, which typically ranges from 1530 nm to 1565 nm, for its optical communication applications. However, CWDM applications have been extended to the E-band, which covers the range from 1360 nm to 1460 nm. This expansion allows for more diverse and efficient use of the optical spectrum, accommodating more data channels while minimizing signal deterioration.

The E-band offers another set of wavelengths suitable for CWDM, thereby enhancing the capacity and flexibility of network design in fiber optic systems. This capability is especially valuable for service providers looking to expand their bandwidth offerings without the need for extensive infrastructure changes. The other bands mentioned do not specifically align with the intended applications of CWDM.